During 1980's U.S. government was evaluating the acquisition of Pacific Division of Pan American World Airways by United Airlines. Pacific Division of Pan American World Airways was serving U.S. - Japan market. At that time, the market share of the airlines serving U.S. - Japan routes was as follows: Japan Airlines 31 % Northwest Airlines 29 % Pan Am World Airways 19 % United Airlines 7 % Four (4) additional airlines 14 %

Calculate the Herfindahl-Hirschman (HHI) concentration index if United Airlines acquire Pan Am World Airways. What type of market is this in terms of concentration?